Heater



FIG. 1 is a perspective view of a heater showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof; and

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is an enlarged view of area 8 circumscribed in FIG. 2 .

The broken lines depict portions of the heater that form no part of the claimed design. The dash-dot-dash lines denote the boundaries of the enlarged detail area of the heater and form no part of the claimed design. 

CLAIM The ornamental design for a heater, as shown and described. 